Process for preparing gluten and wheat starch



United States Patent 2,961,353 a ented Ne 2%, Q6?

than the gluten heretofore produced by the prior art methods. Another object of "this invention is to teach a 2,961,353 method for preparing gluten which has a light color. PROCESS FOR PREPARING GLUTEN AND Some of the advantages and unexpected results of this WHEAT STARCH' i v (1) The wheat starch 1S notadversely affected .bythe Walter A. Carlson and Elliott M. Ziegenfuss, Minneapchange in pH of the dough.

assignols General Mills, a p (2) The wheat gluten is not adversely affected in any fi 0f Delaware of its physical characteristics by the increase in pH of the dough, No Drawing. Filed Sept. 28, 1956, Ser. No. 612,593 (3) T e fat content of the gluten is reduced app re- 2 Claims. (Cl. 127-67) ciably.

Other objects and advantages .to this invention will become apparent upon reading the specifications;

This invention relates to an improved method for sep Various basic inorganic compounds 'may be used to arating wheat flour into wheat gluten and wheat starchincrease the pH of the dough. Illustrative of these basic More specifically, this invention relates to a process for compounds are sodium hydroxide, potassium hydroxide, effecting the above separation wherein a relatively stable sodium carbonate, sodium bicarbonate, calcium hydroxand light-colored vital gluten results. ide, calcium oxide, sodium hypophosphate, and other Wheat gluten contains most of the protein present in similar-compounds. These basic compounds may also be ordinary wheat flour. It is, therefore, an economical characterized as being the'hydroxide's'and oxides of the source of proteins and may be used as a protein suppleelements of groups I and'I'Iin the periodic table and salts ment. It is especially useful in the preparation of highof these compounds with weak acids. It will also be protein bakery products and'cereals. appreciated that since'the ultimate pH desired is ap- The conventional and time-honored steps employed in proximately 7, the water incorporated in the dough may the separation of wheat starch and gluten from wheat be mixed with any substance which will neutralize the flour are as follows: i natural acidity of the flour.

Step 1: Flour and water are mixed'to form a dough. This invention may be illustrated further by reference Step 2; The dough is washed thoroughly with water. to the following examples, in which all parts are ex- During this step the wheat starch and wheat gluten are pressed as parts by weight, and all .percentages are separated, the wheat starch going with the washwa-ter to expressed as percent by weight, unless specified otherwise. form what is commonly called .starch milk and the wheat gluten is left behind. I a

Step 3: The wheat starch is separated from the starch Table I shows the results obtained by preparing wheat milk. The preferred method for effecting this separation gluten from a wheat flourwhich contained 14.6% prois by centrifugation. tein, 0.93% ash, and 2.1% ethyl ether extractable fat, by

Step 4: The washed gluten is dried. This drying ste adjusting the pH of thedough to various levels. may be effected by any one of a number of suitable The procedure employed in this example was as folmethods. Customary methods are by vacuum drying in lows: an oven and by flash or spray drying. 40 A. 500grams of flour and 0 mL-of water contain- Step 5: The gluten is crushed and ground. This step ing the various basic substances were i d {055mm a may beperformed in any conventional method, and, dough in al-Iobart mixer. v w generally speaking, the particle sizes will fall within the B. The dough was allowed to stand for 15 minutes, at, range'of -300 mesh. i which time the pH of the wet, dough was taken.

It has now been discovered that the properties and 45 C. The dough was then washe'dwith water until the physical characteristics of the gluten may be greatly enwet weight of the gluten was about220 grams. hanced by adjusting the pH of the water used to form D. The wet gluten was dried in a vacuum and then the dough. Generally speaking, it has been observed ground in a Raymond mill.

Table l Composition of I 7 Sample Water Used to pH of Percent Weight of Number Form the Dough Dough Ethyl Percent .Recorered Color (Buff) Ether Protein Vital Extract- Gluten in able Fat Grams Tap water 6.0 medium.-. 1.9 83.5 67 2% Na PO4. 8. 9 very light.-. 1. 0 84:0 53 1% NazHPo4 6.9 ligh 0.6 80.5 66 0 5% N33P04. 6.9 medium...-- 0.9 82.0 67 0.5% Naiooa. 8.5 very light--- 0. 5 86. 0 50 0.12% 02,011.. 6.9 medlum 0.7 82.6 66 0.1% 0110 6.8 do 0.6 79.5 67 0.25% Nalcoimn 7.2 do a .6 80.5 66

EXAMPLE H that optimum pH to which the dough should be adjusted 5 is about 7. The preferred range is, therefore, from 6.8 to 7.2. However, it has been noted that higher pHs given an equally satisfactory glutenbut that the total yield of gluten diminishes at pHs higher than 7.2.

It is, therefore, the principal object of this invention to teach and disclose a novel and useful method for preparing an improved gluten product which is more stable Table II shows theresults obtained by preparing wheat gluten fiom a wheat flour which contained .14.7.% tein and 0.92% ash by adjusting the pH ofthe dough with various basic compounds.

The procedure followed in this example was as follows:

A. 250 grams of flour and 250 ml. of make up water 3 containing the indicated amount of alkaline solutions were mixed for about minutes to form a dough.

B. The dough was permitted to stand minutes and the pH of the dough was taken.

4 rate of 8,000 pounds per hour and washed with 60,000 gallons of tap water per hour counter-currently to produce a wet gluten mass and starchmilk.

Eight-pound portions of the wet gluten mass, which are C. The dough was washed with water until the wet 5 about 73 water by weight, were then subjected to vacuum gluten weighed about 120 grams. Q drying at 27 inches vacuum and 35 pounds steam pres- D. The wet gluten was dried overnight in an oven sure for four hours. The dry vital gluten cake was then held at 120-125 C. under 27 inches of vacuum. crushed in a paddle type conveyor and ground to a E. The dry gluten was ground in a Raymond mill particle size falling between 60 and 300 mesh in a Rayusing a screen having of an inch openings. 10 mond verticalmill.

Table II Gluten Millillters of 0.2 N pH of Sample Alkali Added to the Ethyl Weight of Weight of Number the Make-up Dough Percent Ether Ex- Recovered 100 Water Protein tractable Vital Glu- Proteln Fat ten in Recovered Grams in Grams 5 9 79.0 1.36 37 29.2 50 ml. NaOH 8 3 85.0 0. 93 31 26.4 ml. NaOH 6 7 79.1 1.23 37 29.4 50ml. KOH a 3 86.3 0.35 31 26.8 .KOH a 6 79.6 1.25 as 30.2

EXAMPLE III EXAMPLE VII The procedure outlined in Example II was followed Vital wheat gluten was prepared in the same manner except that 2% ammonium bicarbonate and ammonium and quantities as in Example VI except that the tap carbonate by weight of the flour were added to the makewater used to prepare the dough contained 0.08% NaOH up water. The pHs of the doughs in this instance were based on the weight of the flour. The resulting gluten 8.4 and 8.3, respectively. In the case of ammonium had a lighter color than the gluten from Example VI bicarbonate, 31 grams of gluten were obtained, having and the ethyl ether extractable fat was also appreciably a protein content of 84.3% and 1.30% of ethyl ether 35 reduced. extractable fat. With ammonium carbonate, 29 grams Many modifications and variations of the invention as of dry gluten were obtained, having a protein content hereinbefore set forth may be made without departof 85.3% and 1.08% of ethyl ether extractable fat. ing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in EXAMPLE IV the appended claims. Three doughs having a pH of 5.5, 5.7, and 7.3 were Now, therefore, we claim: used to prepare vital gluten as outlined in Example II. 1. In the process for separating wheat gluten and The resulting gluten samples were studied for stability wheat starch from wheat flour comprising the steps of and the peroxide content of the gluten from the dough forming a dough by mixing the flour and water, washing having a pH of 7.3 was about half the peroxide content the dough with water, separating the wheat starch from of the gluten samples from the doughs having a pH of the wash water, drying the gluten and grinding the dried 5.5 and 5.7. gluten, the improvement which comprises adjusting the pH of the dough to a pH within the range of 6.4 to 8.5 EXAMPLE v by the addition of a basic substance and thereby obtaining Gluten separated in the manner described in Example relatively stable lj hp l d gluten I was Studied in respect to the fiffect of P 011 the 60101 2. In the process for separating wheat gluten and wheat of the gluten. Table HI lists the results of these observastarch f wheat fl u comprising the steps f f tions. ing a dough by mixing the flour and water, washing the Table III dough with water, separating the wheat starch from the wash water, drying the gluten and grinding the dried pH of Gluten Color of Gluten gluten, the improvement which comprises adjusting the pH of the dough to a pH within the range of 6.8 to 7.2 5.51 deep bufi. with a basic substance and thereby obtaining relatively g- 2 {f g f i stable light-colored gluten. 9- e0 g eh References Cited in the file of this patent UNITED STATES PATENTS pH orthissam leadinsted with HCI, thepHottheremaintng samples 2 437 036 Murer et 1 Mar. 2 943 were adjusted with NaOH.

I This sample was observed to have the lowest peroxide content. 1 lmlel' DEC. 14, 1948 Recovery of gluten diminished with these amples- 2 516 117 H 1 et 1 J 25 1950 EXAMPLE VI OTHER REFERENCES Wheat flour (one part) having a weighted protein con- Wheat Protein Saved, Sci. News Letter, July 3, 1943, tent of 14.6% and an ash content of 0.98% was mixed p. 3. with tap water (0.9 part) in a dough mixer. The dough American Miller and Processor, April 1944, Whe

was then fed continuously to a washer-extractor at the Flour, pp. 32, 34, 37 and 78. 

1. IN THE PROCESS FOR SEPARATING WHEAT GLUTEN AND WHEAT STARCH FROM WHEAT FLOUR COMPRISING THE STEPS OF FORMING A DOUGH BY MIXING THE FLOUR AND WATER, WASHING THE DOUGH WITH WATER, SEPARATING THE WHEAT STARCH FROM THE WASH WATER, DRYING THE GLUTEN AND GRINDING THE DRIED GLUTEN, THE IMPROVEMENT WHICH COMPRISES ADJUSTING THE PH OF THE DOUGH TO A PH WITHIN THE RANGE OF 6.4 TO 8.5 BY THE ADDITION OF A BASIC SUBSTANCE AND THEREBY OBTAINING RELATIVELY STABLE LIGHT-COLORED GLUTEN. 